Clocks Fall Back One Hour Tonight, It'll Be Dark Before 5 P.M. Sunday

DENVER (CBS4) - Daylight saving time is about to end in the United States. It's officially over at 2 a.m. on Sunday, November 1. That means you'll want to set your clocks back one hour before going to bed Saturday night.

Daylight saving time dates back to 1916 when Germany adopted the practice to save energy for the war effort. Many countries followed suit including the United States.

But daylight saving time has fostered controversy ever since it was created. According to timeanddate.com it was repealed in the United States shortly after being introduced in 1918, but several cities continued to use it, including Pittsburgh, Boston and New York.

More recently the Energy Policy Act of 2005 gave every U.S. state and territory the right to opt out of daylight saving time. Arizona is the only state in the lower 48 that exercises that right. The entire state stays on Mountain Standard Time all year except for the Navajo Nation in northern Arizona. They follow DST to stay on the same time as their territory in nearby Utah and New Mexico.

Outside of the lower 48, Hawaii and U.S. territories including Puerto Rico, Guam and the Virgin Islands keep their clocks the same all year, opting not to follow the practice of daylight saving time.